Cells of the Immune System Flashcards
Does the innate immune response occur over hours to days or days to weeks?
Hours to days, very quickly before adaptive immune responses develop
Are innate immunity responses mechanisms in place before or after an infection occurs?
They are mechanisms in place before the infection occurs.
Do innate immunity responses change with repeated exposure to microbes?
They do not change
Describe PAMPS
Pathogen-associated molecular patterns. They are structures that simulate innate immunity
What are DAMPS
Damage-associated molecular patterns. They are molecules produced by or released from damaged and dying cells
Are PAMPS and DAMPS part of the innate or adaptive immunity?
Innate
What are the physical and chemical barriers in the innate immune system?
Epithelium, antimicrobial chemicals, lysozome in sweat, lactic acid in vagina, HCl in stomach)
List 4 cells in the innate immune response
Phagocytic cells, dendritic cell, mast cells, NK cells
Are Phagocytic cells, dendritic cell, mast cells, NK cells part of Innate immunity or Adaptive?
Innate imunity
is the compliment system part of the innate or adaptive immune response
innate
Does the adaptive immune response occur over hours to days or days to weeks?
days to weeks, slower onset
Does the innate or adaptive immune system respond first
innate is faster, adaptive is slower
What are the 2 types of lymphocytes that the adaptive immune system is known for
T and B lymphocytes
Describe clonal selection
lymphocytes with unique receptors are activated by epitomes on antigens
Simply, when an antigen enters the body, a single B and T cells reproduce with specific receptors to recognize that specific antigen
What is an epitome? Which system is it part of?
- The part of antigens that is recognized by a lymphocyte receptor
- Adaptive
Describe how the adaptive immune system is diverse, has memory and is systemic
-The immune system is diverse because each lymphocyte clone has a distinct antigen receptor.
-It has memory because, after the exposure to an antigen, the immune system has memory cells that respond to next exposures
-It is systemic because you can have an infection in one area of the body that moves to all systems
Are adaptive immune system responses positive or negative feedback loops
Positive: They amplify the reaction to a response, but there are control mechanisms to balance the response
What are the 2 types of adaptive immunity
- Humoral: antibodies produced by b-lymphocytes defends against microbes and toxins
- Cell-mediated: Mediated by T lymphocytes, destroy microbes that survive inside phagocytes
What is the main cell in humoral immunity
antibodies, produced by b-lymphocytes
What is the main cell in cell-mediated immunity
T-lymphocytes
Where does hematopoiesis take place
in the bone marrow
What are the options that hematopoietic stem cells can turn into
Common lymphoid precursor or common myeloid precursor
What do common lymphoid precursor cells turn into
B cells, T cells, NK cells
What do common myeloid precursor cells turn into
Neutrophils, eosinophils, basophils, macropages/dendritic cells, platlets
What is a neutrophil classified as and what does it arise from
a white blood cell, comes from a common myeloid precursor cell.
What is a neutrophil’s major function?
Destroy pathogens by phagocytosis
What is a neutrophil’s life span in tissues
1-2 days
What is an effector cell
a cell that is actively participating in killing invadors in the immune system
What cell is an oxidative burst associated with
neutrophils
What are the values for neutropenia?
Mild <1500
Moderate <1000
Severe <500
All in ANC (absolute neutrophil count)
What does neutropenia cause a predisposition for
severe bacterial infections, ulcers, absesses, gingivitis
Where do macrophages arise from
Common myeloid precursors which differentiate into monocytes (1 nucleus). They circle the bloodstream and then turn into macrophages
When do macrophages become activated
in response to an infection
How do macrophages kill pathogens
by phagocytosis and eliminating dead host cells
What can a macrophage act as?
an APC (antigen-presenting cell).
Macrophages can ingest and breakdown an invader, display it on their cell surface, and show it to T-lymphocytes to see a pathogen
What are tissue resident macrophages derived from
yokl sac or fetal liver precursors during fetal development
What are some of the special kinds of macrophages around the body?
Kupffer cells in liver
alveolar macrophages in lung
microgleal cells in brain
What are sentinel cells
ditect microbes and secrete cytokines to initiate and amplify immune responses
What is the most important APC
dendrites- capture microbial proteins at infection and bring to lymph nodes, present t cells to initiate adaptive immune response
What do eosinophils do
circulate in the blood until recruited into tissues
White Blood cells- respond to infections
Where are eosinophils found
Blood, tissues, GI/GU tracts
What is eosinophils MOA to kill parasites
contain enzymes that are harmful to cell walls of parasites, release contents of granules after binding to a parasite
Where are mast cells found
tissues, usually by small blood vessils or nerves
What does a mast cell do when activated
release potent inflammatory cytokines and lipid mediators. They do not phagocytize, they degranulate
What cell receptor does mast cells have that is very important in allergies
IgE receptor that binds to antibodies
What are basophils and what are they similar to
Circulating granulocytes, express IgE, similar to mast cells. Only small impact
Why dont we see mast cells or macrophages in the blood stream
They are tissue residents, not circulating in the blood stream.
What happens when a monocyte enters the tissue?
It turns into a macrophage
Where do B cells mature?
In the bone marrow
Where do T cells mature
in the Thymus
What do you call mature T and B lymphocytes that haven’t encountered an antigen?
naieve lymphocytes
When does clonal expansion occur, and what is this an example of?
when T and B lymphocytes are exposed to an antigen. An example of diversity, where they have different expansion to pathogens
What are the different jobs of effector cells and memory cells?
Effector cells eliminate the antigen and memory cells help have quicker responses to future infections
What do CD4 cells turn into
Helper T cells (secrete cytokines, stimulate other immune cells)
What do CD8 cells turn into
directly kill infected cells
What do regulatory t cells do
supress and regulate immune response, maintain self-tolerance
What do memory T cells do
remain in a cycling state, rapidly responding to future exposures
What do effector B cells do
release antibodies that bind to pathogens or foreign substances, neutralizing them
What do memory B cells do
memory cells that give long term immunity by responding to future exposure to same antigen
What are 3 phagocytic cells
macrophages, neutrophils, dendritic cells(but usually not dendritic)
What are sentnel cell examples?
Macrophages, dendritic cells, mast cells
- Tissue residents waiting for microbe to enter to kill
What are 3 examples of granulocytes
-Contain granuel contents that kill invadors or pathogens
Neutrophils, eosinophils, basophils, Mast cells
Which cells have lymphocyte lineage
T cells, B cells, NK cells
Name 3 APC’s
Dendritic cells, macrophages, B cells
How does the compliment system respond to infection
Blood proteins that are activated on microbial surfaces, tagging them for destruction by phagocytes (opsonization)
What is the main function of the compliment system
Promote phagocytosis of microbes, stimulate inflammation, and induce lysis of microbes
How do you differentiate between T and B cells?
You can’t use a microscope- Use Flow Cytometry to differentiate
In an infection, do neutrophil counts in blood go up or down
up- increases because neutrophils go to site of infection
